In ancient times, Godzilla and many other monsters of enormous size thrived in a radioactive climate as Earth's atmosphere was still developing. These creatures depended on radiation to survive, similar to later plant species that would feed off sources of sunlight to develop photosynthesis. Among these creatures was a parasite-like entity that fed off these monsters. While the parasite creatures weren't strong enough on their own to kill their prey, they would hunt in groups. Using their numbers, they would slay a beast and then lay their eggs in the carcass. This gave their young an energy source, as they would feed off the radiation in the host until they were strong and large enough to hatch and fend for their own.

250 million years later, a mining excavation in the Philippines in 1999 uncovers a large underground chamber. Inside is an almost fossilized set of gigantic bones. Giving off radiation, the bones have two gapping holes where spore-like encasings are found. One is still intact, while the other had hatched and left a path of destruction out to sea.

Shortly afterwards, in Japan, tremors and growing signals are detected around the Janjira nuclear plant in Kanto. The tremors grow stronger, along with electronic interference, until the plant is hit with a massive quake, with the epic center being the facility itself. Many staff die while the cooling towers collapse under the magnitude. The area is evacuated and the section of Kanto placed as a quarantine zone. The organization Monarch, which investigated the bones in the Philippines, arrives to witness the devastation. They find an entity cocooning itself to one of the reactors, slowly absorbing the radiation. They build a facility around it to study the creature which they dub M.U.T.O. (Massive Unidentified Terrestrial Organism).

In 2014, the signals start again. The source is the ruins of Janjira where the cocoon is dormant and the radiation supply from the reactor almost gone. Fearing the worst, Monarch electrocutes the spore to kill the entity. However, the attack fails, and emerging from the cocoon is an insect-like monster with four legs. The mammoth being slams one of its claws to the ground which unleashes a massive electromagnetic pulse (EMP), disabling everything electronic in the facility. The creature then flies off to find another source of radiation to feast on.

Out at sea, an unlucky Russian nuclear submarine is attacked and carried off by the flying MUTO. It drops the submarine in the foliage on Honolulu, Hawaii. The creature then proceeds to feast on the nuclear elements of the vessel, until its interrupted by F-18 jets. In retaliation, the creature releases an EMP which downs the jets. It then proceeds inland toward the Honolulu airport, but is intercepted by Godzilla. The King of the Monsters heard the MUTO's echolocation call, and sought out the source to destroy it. The MUTO flies away, with Godzilla in pursuit.

As it turns out, the call was for a mate, and a spore-like casing that was recovered from the Philippines answers. Stored in Nevada, a female awakes and makes its way toward San Francisco where the pair communicate a meeting grounds. The winged male steals a nuke in the area, which is engaged and was originally going to be used as a weapon against them, and meets the female so they can begin to care for their soon to be hatched young. Godzilla arrives to do battle, and the female protects a nest of creatures it just gave birth to before it joins the male in fighting the King of the Monsters. United, the two prove to overpower Godzilla, but the female is distracted after an explosion kills their yet to be hatched children at the nest. Capitalizing on the opportunity, Godzilla uses his tale to slam the male MUTO into a building. The impact kills the creature, with debris lodged clear through its head due to the force of the blow.

Powers / Weapons

Flight

Using its wings, the male MUTO was able to take flight. The exact speed the creature was able to fly at is unknown.

Electromagnetic Pulse

The male MUTO is able to release an electromagnetic pulse from its claws. The claw would light up before discharging the EMP (Electromagnetic Pulse), which would disable all electronic devices within range. To unleash the pulse, it would typically slam its appendages into the ground. However, the creature was able to discharge the blast while airborne, so there was another unseen way it could create the EMP.

Advanced Echolocation

The MUTO species was equipped with advanced echolocation. This permitted the creature to communicate with other MUTO and also detect sources of radiation.

Due to this power, the male was able to locate and destroy a Russian nuclear submarine and also intercept a nuke in the bay of San Francisco.

Background and Trivia

During the film, the military states the EMP blast as being five miles around the creature in all directions, for a total sphere of about ten miles (16,093 meters) in width. However, the male was able to unleash an EMP while flying above the bay that knocked out power all the way to downtown of the city. San Francisco is 13 miles wide, meaning the blast radius was considerably larger than the military projected.

Sources differ on the height of the male MUTO. Godzilla: The Art of Destruction notes 300 feet (91 meters) as the height. On the US Blu-ray, a feature called MONARCH Declassified: The Godzilla Revelation lists 200 feet (60 meters), although this is a fictional, in-universe estimate from a reporter. Most sources, however, don't note any statistics for the creature.

Following the discovery of the spore-like constructs in the Philippines in 1999, the remaining encasing was taken into US custody. Many scientists, including Ichiro Serizawa, had determined the casing to be devoid of life. Being radioactive, the encasing was stored in Yucca Mountain nuclear waste repository.

Fifteen years later, as the male MUTO emerges, he uses echolocation to call out to a mate. The female responds to the call and emerges from her long dormant state. At 340 feet tall, and containing six legs with two arms, the female is massive in size compared to the male of the species. The female quickly destroys the nearby Las Vegas strip before heading westward on a collision course with the male that would place them both in San Francisco.

The military devises a plan to lure the creatures miles off the coast of San Francisco and then nuke them. The hope is a bomb would work both as the bait and final weapon against them. The plan is set into motion, using trains to deliver the bombs to San Francisco in order to avoid interface from the electromagnetic pulse (EMP). The bait proves too tempting, though, and the female MUTO makes a slight detour. She ambushes the train on a trestle bridge, killing almost all of the crew and consuming all but one of the nuclear weapons. The last nuke is airlifted out while the female continues her trek to the Bay Area.

Later, after the male has secured the final nuke in San Francisco, the female emerges. The male delivers the prize while its apparent that the female is pregnant with hundreds of babies. Using Chinatown as a nesting ground, the female uses her massive claws to dig into the Earth and lay spore-like eggs around the nuke.

Sensing the call, Godzilla arrives to kill the MUTO and the male is the first to engage. Godzilla is too much for it, but the female MUTO joins in and turns the tide. The two creatures use their claws to rip large holes in the King of the Monsters, gaining the upper hand. The duel is interrupted, though, when a soldier in the military destroys the nest with an explosion after moving the nuclear warhead out of the area. Godzilla uses this moment to assault the male, killing him but getting himself buried under the building that was utilized as a weapon.

In a frenzy, the female MUTO chases the military trying to take the nuclear warhead out of San Francisco. Meeting them at the dock, she kills the crew after they had loaded it onto a boat and unleashes an EMP. An injured Godzilla intercepts the female before she can secure the nuke. Forcing her jaws open, the King of the Monsters breathes an atomic ray down her throat. The flame bursts through the neck, severing the head from the body: killing the last of the MUTO.

Powers / Weapons

Electromagnetic Pulse

The female MUTO is able to release an EMP (electromagnetic pulse). The resulting EMP would disable all electronic devices for miles.

This power was not seen being used by the female, although the film did show the aftermath. This includes a downed commercial airliner that got too close and when the power went out at the Las Vegas strip. It's unknown how the power was released, but it's assumed to be through the claws like the male. Oddly, the female did not use this power to fend off a group of helicopters that were attacking her as she left the Las Vegas strip, although the male demonstrated a similar behavior when attacked by helicopters in Honolulu.

Advanced Echolocation

Both the female and male MUTO have a form of advanced echolocation. This ability was used to detect other MUTOs and also sources of radiation.

This power allowed the female MUTO to successfully intercept and steal one of the nuclear warheads that was traveling by train before it was able to arrive in San Francisco.

Background and Trivia

The stats for the MUTO are surprisingly obscure. Many sources, both in the United States and Japan, do not list the size or mass of the creatures. Those sources that do are sometimes contradictory. The 2014 book Godzilla: The Art of Destruction lists two separate height stats for the female. The publication cites both 440 feet (134 meters) and 340 feet (104 meters) as sizes for the female. The creature was not larger than Godzilla, so it's assumed the 440 feet figure was a typo.

To confuse matters, there is a special feature on the US Blu-ray called MONARCH Declassified: The Godzilla Revelation. This is a fictional special feature, that is intended to act like a reporter is doing a follow up story after the battle between Godzilla and the MUTO. During the feature, the reporter cites that the Male MUTO was "probably around" 200 feet (60 meters) while the female might have been between 250-300 feet (76-91 meters). Given that the reporter seems unsure of the figures he is stating, it's likely he might have been inaccurate even if he had the correct height of Godzilla.

To further confuse things, there is a different special feature on the US Blu-ray
called Ancient Enemy: The M.U.T.O.s. In this feature, the production crew refers to them as "400 foot parasites".